Quitting smoking adds an average of seven years to a parent's life, improves the health of the spouse, eliminates the majority of secondhand smoke (SHS) exposure of the children, reduces tobacco-related poor pregnancy outcomes, eliminates the greatest cause of house fire mortality, and improves the financial resources of the family. Much research has been done developing techniques to enhance the provision of evidence-based tobacco control in the adult primary care practice setting, but parents may not have a primary care clinician and even when they do, often visit their child's doctor more frequently than their own. We developed an intervention to address parental smoking in the child healthcare setting that employs, in combination, evidence-based smoking cessation techniques including the 5 A's (Ask, Advise, Assess, Assist, Arrange), proactive referral to regional and national "quitlines," and pharmacologic management of tobacco dependence. We will be testing this previously developed, pilot tested, and theoretically-based intervention designed to improve adherence to evidence-based guidelines at the clinician level, facilitate change at the parent behavior level, and lead to implementation of systems changes at the practice level. We will compare our intervention to an "attention" control consisting of handing out a current best practice tobacco control pamphlet. The proposed study will be a 60-site, group randomized controlled trial (RCT) of effectiveness that builds on focus group, feasibility, and efficacy work supported by the National Cancer Institute, the Flight Attendant Medical Research Institute, and the Robert Wood Johnson Foundation. It will be conducted in the American Academy of Pediatrics (AAP) Pediatric Research in Office Settings (PROS) practice-based research network, the largest research network of pediatric practices in the United States. Findings will be widely reproducible and transportable through the more than 700 PROS practices (which provide care to over 3 million of the nation's children) and to other practice networks and practices nationally. This research will contribute to the NCI's efforts to defeat cancer through the National Cancer Program and is in exact alignment with NCI's Strategic Plan to develop and apply evidence-based interventions for preventing cancer. This trial will help the nation to "preempt cancer at every opportunity" by "accelerating progress in cancer prevention" and to focus efforts on the young adults and children who form the future of a cancer-free U.S. population.